Bends in volcanic hotspot lineaments, best represented by the large elbow in the Hawaiian-Emperor chain, were thought to directly record changes in plate motion. Several lines of geophysical inquiry now suggest that a change in the locus of upwelling in the mantle induced by mantle dynamics causes bends in hotspot tracks. Inverse modeling suggests that although deep flow near the core-mantle bo...

It is well known that transcription can induce torsional stress in DNA, affecting the activity of nearby genes or even inducing structural transitions in the DNA duplex. It has long been assumed that the generation of significant torsional stress requires the DNA to be anchored, forming a limited topological domain, because otherwise it would spin almost freely about its axis. Previous estimate...

We present a model of nonspecific cooperative binding of proteins to DNA in which the binding of isolated proteins generates local bends but binding of proteins at neighboring sites on DNA straightens the polymer. We solve the statistical mechanical problem and calculate the effective persistence length, site occupancy, and cooperativity. Cooperativity leads to nonmonotonic variation of the per...

Various neurological forms of decompression sickness are classified and an inquiry two and a half to five and a half years after the acute illness is reported. One hundred subjects with decompression sickness of the central nervous system were examined. In more than half of the cases the clinical picture was that of chronic encephalomyelopathy, vegetative neurosis, or psychosomatic symptoms. Sy...

Not much is known about the medical, psychological, and performance effects of aging among US Navy divers. The possibility has been raised that several medical consequences of diving, especially decompression sickness and osteonecrosis, may be complications of the aging process.1,2 Both decompression sickness and osteonecrosis have been found to occur more frequently among older divers than amo...

In a cycling time trial, the rider needs to distribute his power output optimally to minimize the time between start and finish. Mathematically, this is an optimal control problem. Even for a straight and flat course, its solution is non-trivial and involves a singular control, which corresponds to a power that is slightly above the aerobic level. The rider must start at full anaerobic power to...

The design, fabrication, characterization, and modeling of basic building blocks of plasmonic circuitry based on dielectric-loaded surface polariton waveguides, such as bends, splitters, and Mach-Zehnder interferometers are presented. The plasmonic components are realized by depositing subwavelength dielectric ridges on a smooth gold film using mass-production-compatible UV-photolithography. Th...

We report the design, fabrication and characterization of compact gradual bends for channel plasmon polaritons (CPPs) being excited at telecom wavelengths. We obtain high-quality near-field optical images of CPP modes propagating along a bent V-groove in gold, which indicate good CPP mode confinement in the groove and efficient guiding around the compact S-bend connecting two 5-mum-offset groov...

Acclimatization to decompression stress has been reported in caisson workers and helium-oxygen divers; however the alternative notion that the risk of decompression sickness increases with successive days of diving is widespread. We examined 201 multi-day series of 2 to 29 diving days identified retrospectively in a database of occupational air dives for evidence of acclimatization or sensitiza...